a) Field of the Invention
The invention is directed to a hinge for sheet-metal cabinet doors, machine casings, housing covers, or the like, comprising a first hinge part, such as a hinge leaf, with one or more countersunk openings for fastening screws and with a second hinge part articulated at the first hinge part, such as a hinge support or another hinge leaf, provided with one or more openings for fastening screws, wherein the countersunk openings of the at least one hinge part are constructed as elongated holes.
b) Description of the Related Art
A hinge of the type mentioned above is already known from the German Utility Model 29 51 712.1 of the present Applicant. Compared with previous constructions, for example, those cited in this Utility Model as prior art, the screw-on hinge known from this Utility Model already overcomes certain disadvantages occurring particularly in sheet-metal cabinet doors; that is, sheet-metal cabinet doors tend to warp during production or when mounted, which can impede opening and closing of the door, especially when close fits are provided between the door frame and door leaf. In order to avoid this disadvantage, it is suggested in the Utility Model to construct the openings in the hinge leaves as elongated holes. A certain adjusting possibility will result depending on the orientation of these elongated holes. If the orientation is parallel to the hinge axis, the height of the door leaf can be adjusted with respect to the door frame, for example. On the other hand, if the orientation is vertical to the hinge axis, the vertical gap between the door leaf and door frame can be adjusted with respect to its width.
In the reference cited above, the hinge comprises two leaves, which offers the possibility of providing a leaf with elongated holes oriented parallel to the hinge axis and the other leaf with elongated holes oriented perpendicular thereto, so that a two-dimensional alignment possibility is provided.
The reference states that it is advantageous to countersink these openings and, instead of standard screw bolts and nuts for fastening the hinge leaves, to use screws which are screwed into rivet nuts or blind rivet nuts. Cap screws whose head dimensions are adapted to the dimensioning of the countersink on the outer side of the hinge leaf are provided as fastening screws. On the other side, the rivet nuts or blind rivet nuts form an outer rivet collar having an outer diameter to which a (necessary) countersink on the inner side of the hinge leaf is adapted. In this way, the projecting rivet collar can be received on the one hand and its interfering influence can accordingly be eliminated and, on the other hand, this rivet collar can be utilized for alignment and for additional support of the hinge plates.
However, it is disadvantageous that rivet nuts or blind rivet nuts of the type mentioned above which project over the sheet-metal surface and are fixedly connected with the sheet metal of the door leaf or door frame can only be used in certain cases. If the fastening means are to be completely removed for certain purposes or if the projections are bothersome, nuts which are riveted in in this way cannot be used.
A further disadvantage of the known arrangement consists in that the fastening screw can move in the elongated hole along the longitudinal extension thereof when the fastening screw is not properly tightened. This risk is particularly high when the sheet-metal cabinet is subjected to a shaking movement during transport or during operation. A further disadvantage consists in that the elongated hole also remains partly visible when the fastening screw is mounted and there remain openings acting as dirt collectors which can be troublesome, e.g., when a switching cabinet is used in the food industry.
A further disadvantage consists in that the known hinge must always be adjusted even when the cabinets are manufactured in a very precise manner. The reason for this is that the known hinge has no "zero setting" or "reference position" which could be used when an adjustment was really not required in terms of the basic design of the cabinet.